I've found that beiing a sniper is pretty pointless unless you are working well in a team and have radios. When I'm a sniper I spend more time calling locations and directing movement than actually shooting. More often than not when I take a shot I'm greeted with a hail of pellets from the rest of the opfor that I can't answer to with a bolt action rifle or gas pistol. I good sniper in a good location calling opfor locations can be the difference between success and faliure. It also feels great when you see the wtf look on someones face when they get hit and never heard a shot.
Other subtle problem with sniping is that the range of your gun is not much better than an AEG so you better hit first time!